zorro: Constify 'struct bin_attribute'

The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory.  Make use of that to protect them against
accidental or malicious modifications.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/20241216-sysfs-const-bin_attr-zorro-v1-1-220a38d49507@weissschuh.net


Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>